Delhi murder: "No valuables were missing," said police officer Devender Arya. It was also suspicious that after brutally killing the three others, the so-called intruders spared Suraj.

19-year-old Suraj told police that he was "tired" of reprimands from his parents.

New Delhi:

Highlights

Suraj told police that he was "tired" of reprimands from his parents

He spent evening looking at photo albums, killed parents later

Several clues in the murder case pointed at the teen son

An apparent robbery but nothing missing, three of a family killed and a fourth with just an injured finger. The murder of a man, his wife and daughter in their home in south Delhi's Vasant Kunj baffled the police until several clues pointed at the fourth member of the family - the teen son.

19-year-old Suraj Verma was arrested on Wednesday. He told the police that he was "tired" of reprimands from his parents - for not studying, for skipping college and lately, for "wasting time" flying kites on August 15 Independence Day.

Seething with rage after his father Mithilesh Verma allegedly beat him that day, Suraj decided to "teach his family a lesson", said the police.

On Tuesday, he went out with his friends and, on his way back, bought a knife and a pair of scissors.

That evening, he spent time with the family, going through photo albums with his parents till midnight.

Suraj woke up at 3 am and went straight to his parents' room. He allegedly stabbed his father, 44, multiple times in the chest and stomach. His mother Sia, 38, was roused from her sleep and she screamed, but was immediately stabbed.

The teen then allegedly went to his 15-year-old sister's room and stabbed her in the neck. His mother, wounded but still alive, tried to save the girl but he repeatedly stabbed her, the police say.

He allegedly ransacked the house and washed off his fingerprints from the knife. After around two hours, he alerted neighbours and claimed robbers had killed his family.

But his story didn't check out, the police said. "No valuables were missing," said police officer Devender Arya. It was also suspicious that after brutally killing the three others, the so-called intruders spared Suraj.

A forensic team soon found that Suraj had washed his footprints in the bathroom and also the knife used to kill the family.

Suraj had allegedly faked his own kidnapping a few years ago but was caught out.

The teen had flunked his Class 12 exams and had been pulled up repeatedly by his father.

"He felt he failed his Boards since his father had asked him to supervise the construction of their house. He was upset about being blamed," said a police officer. His father arranged his admission in a private institute in Gurgaon so he could get a diploma in civil engineering and become a contractor like him.

Suraj also resented his sister, believing she told on him and revealed details of his life to their parents.